1. Field of the Invention
The invention relates to an extension cord clamp for reinforcing the connection between an extension cord and a cord from an electric device.
2. Description of the Related Art
The use of extension cords is very common in both household and commercial applications. A common problem is the necessity of having to repeatedly reconnect a lawnmower extension cord, a power-tool extension cord or the like. Possible solutions to this problem range from simply tying a knot in the cords around the connection to elaborately complicated devices, some of which have been disclosed in patents.
Among the many patents disclosing devices for reinforcing the connection between plugs and sockets are U.S. Pat. Nos. 3,048,810 to Steen, 3,223,958 to Prohl, 3,344,393 to Hendee, 3,609,638 to Darrey, 4,143,934 to Siebert and 4,643,505 to House et al.
These and other known devices which relate to reinforcing the connection of extension cord sockets and plugs all have disadvantages and limitations.
Firstly, most of the above patents disclose housings which enclose the plug and socket connection in its entirety. This feature, naturally, limits the shapes and sizes of connectors that may be used with the device. Also, the entire housing will be opened at once, so that both connectors come free at the same time.
One patent which belongs to the above family is 3,223,958 to Prohl. Prohl discloses a sheet metal frame to which a plug-connector pair is clamped by means of two resilient arms. It is obvious that this device is quite limited as to the size and shape of connectors that may be used. Also, if two substantially different sizes of connectors were to be used, this device would be rendered ineffective, since only one of the two connectors would be clamped into the reinforcement.
Secondly, some of the devices disclosed in the above patents apply pressure to the plug and socket and thus put unnecessary strain on the plug-cord or socket-cord connections, which may lead to bad connections and/or to the connections being shorted or disconnected.
Thirdly, some of the above patents disclose devices which are complicated with respect to their construction and thus are complicated to use and can only be manufactured at relatively high cost.
Fourthly, while some of the above patents feature full enclosure housings for the plug-socket connection, others leave the connection prone to external shock influences. A patent belonging to the latter family is 3,609,638 to Darrey. It is conceivable that when the clamping device in accordance with the Darrey patent falls on the ground, one or both of the butterfly clamps may open momentarily and release the extension cord. Also, the device is likely to open and release the cord if it is stepped upon.